Management systems are known (for example, Patent Document #1) which manage collectively the operational states of working machines such as a large number of construction machines or transportation vehicles or the like which are present in several locations. With these management systems, various types of sensor are mounted on the working machines, and operational data (data such as, for example, working time, engine rotational speed, battery voltage, engine cooling water temperature, remaining amount of fuel and the like) are generated based on the detection signals from those sensors. This operational data for the working machines is gathered by a server via a computer network which includes a wireless communication network. And the server accumulates the operational data for the working machines, and automatically performs supply of this operational data to the user terminals via the above described computer network.
Patent Document #1: Japanese Patent Laid-Open Publication 2002-91547.